The x-factor Israel Folau is forecast to bring Australian rugby could take until the end of the year to be fully realised, says Waratahs teammate Lachie Turner.

Turner, one of at least eight Waratahs players who can play in their back-three combination, has the credentials to know how long it will take the former NRL and AFL player to fully adapt. He has played and trained alongside three of the biggest league converts to the 15-a-side game.

In 2006 at the Waratahs Academy, Turner trained against league converts Wendell Sailor and Mat Rogers who were then at the franchise. After stepping up to Super Rugby, Turner was a teammate of Lote Tuqiri.

Turner had always been impressed by the athleticism of Sailor, Rogers and Tuqiri and believes Folau has already shown that trait.

Like so many, Turner was highly impressed by Folau as he played at fullback for the Waratahs in all three trial matches against the Rebels, Blues and Crusaders before for their season-opener against the Reds on Saturday night in Brisbane. Folau is expected to start at fullback against the Reds, although he has the versatility to switch to the wing.

"Matty Rogers, Wendell and Lote...have all been great athletes. That is certainly something that Izzy has in common," Turner said. "He is a strong ball runner, has great hands. Compare him to the guys who have been before...there is no reason he can't be a stand-out like those guys."

Turner said Folau has already proved to be a dream to play outside of. "He has picked up the intricacies of rugby extremely quickly," he said.

"It has been a pleasure to play outside him so far. He puts a lot of doubts in defence and that certainly buys you a bit of extra time outside him. When you have a guy like Izzy there, defence always has one eye on him which means there is one less eye on everybody else. It takes pressure off you."

Turner still believes Folau will need time to fully settle in to rugby which - before joining NSW in December - he last played at high school and even then for only a handful of games.

"I think it is too early to tell," Turner said. "He is a great athlete and I am sure by the end of the year we will start to see little bits of individual brilliance that set him out from other people...that he has developed his own little thing where people can say that's what makes him stand out. But we will wait and see for what that is going to be."

But Turner is confident Folau will be enough of a headache for the Reds on Saturday, and expects they have schemed ways to stymie his impact.

"They will try to find a way to pressure him," Turner said. "They will rush up in the 'D' and try and prevent the ball getting to Izzy. We just have to make sure we earn the right to go wide and...give space to those guys. And that starts up front in the ruck and maul. If we can do that, I am sure we will have a good night. Give [the NSW back three] space and they will make you pay."